@inproceedings{
    muswat,
    author = "Mannila, Heikki and Ukkonen, E.",
    pages = "34-42",
    booktitle = "SWAT 88: 1st Scandinavian Workshop on Algorithm Theory",
    year = "1988",
    editors = "R. Karlsson and A. Lingas",
    title = "Time parameter and arbitrary deunions in the set union problem"
}